Going Linear with the Caiman

Is there anything limiting the type of 10 uF cap you can use to replace the Caiman resovoir cap with, i.e. not physical space (a problem) but dielectric strength? Is there a reason why Stan had a special 16V 10,000uF made or was it that it just had to be dielectrically strong enough to take the 15V power supply? I can't see a problem in using a polyprop cap with say 400 V dielectric strength in there but then I'm a physicist not an electronics engineer.;)

Cheers Andy

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Originally Posted by OLED

Is there anything limiting the type of 10 uF cap you can use to replace the Caiman resovoir cap with, i.e. not physical space (a problem) but dielectric strength? Is there a reason why Stan had a special 16V 10,000uF made or was it that it just had to be dielectrically strong enough to take the 15V power supply? I can't see a problem in using a polyprop cap with say 400 V dielectric strength in there but then I'm a physicist not an electronics engineer.;)

Cheers Andy

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My guess would be that stan had the original resevoir cap made to match the original switching supplies that he sells. So I don't think those considerations will apply to using a linear supply in quite the same way.

Power supply design expert Teddy Pardo simply recommended a film or tant cap of suitable voltage rating, nothing more specific than that. So I don't think anything fancy is required. :)

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Originally Posted by HighFidelityGuy

Power supply design expert Teddy Pardo simply recommended a film or tant cap of suitable voltage rating, nothing more specific than that.

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That's what I did - 2 x 10uF metallised polyester film fit perfectly in the gap vacated by the electrolytic and should offer much faster response. The reality is that it does sound very good indeed, having the edge in dynamics and fine detail.

Hi Martin,

Any reason why you put in two film caps?

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Originally Posted by HighFidelityGuy

Am I likely to gain any sort of improvement by swapping this to a bridge made out of 1N5822 schottky diodes?
EDIT: I just thought; the 1N5822 is 40V. I'm currently feeding my bridge with about 24V AC and getting about 38V DC out the other end. Are 1N5822 diodes still suitable for this application?

Thanks. :)

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I think you'd have to try schottkys & see if there is any difference yourself tbh. There won't be a lot between a fast rectifier & schottkys in theory, practise might be a different matter though ;)

I'll have a look about for some 60V rated versions, yes 38V is cutting it a little close :lol:

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Originally Posted by OLED

Any reason why you put in two film caps?

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Because they fit and it gives me 20uF smoothing :)

60V schottky diodes rated at 3Amp - SR360, 5Amp - SR560

A quick suggestion is to type schottky into ebay search, there are loads of them :eyebrows:

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Originally Posted by Reid Malenfant

60V schottky diodes rated at 3Amp - SR360, 5Amp - SR560

A quick suggestion is to type schottky into ebay search, there are loads of them :eyebrows:

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Awesome, thanks Mark.

I might look at swapping the bridge in my supply to these to see if it makes any difference. I'll probably not do it for a while though as I don't want to change too many things at the same time.

Cheers. :)

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Originally Posted by MartinT

Because they fit and it gives me 20uF smoothing :)

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Yep, very clear that one:)

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Originally Posted by leo

I think Nicks circuit was for differential output dacs, I'm still wanting to try one with the Sabre, it does make sense to try something cheaper with the Bdac, something which doesn't scare everybody off price wise :)

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Hi Leo,

I really want to try out the same valve output stage. Unfortunately, I didn't grab the schematic while I can (audio-talk seems to be down). Do you think it's okay to send me a working link or a copy of it?

Thank you!

Edit: Oops, nevermind, the site's up again!